SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityAnalyzed

CVE-2025-48877

Prior to version 3.4.4 of the `stable` branch, version 3.5.0.beta5 of the `beta` branch, and version 3.5.0.beta6-dev of the `tests-passed` branch, Codepen is present in the default `allowed_iframes` site setting, and it can potentially auto-run…

HIGH 8.1EPSS 0.41%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.41%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Discourse is an open-source discussion platform. Prior to version 3.4.4 of the `stable` branch, version 3.5.0.beta5 of the `beta` branch, and version 3.5.0.beta6-dev of the `tests-passed` branch, Codepen is present in the default `allowed_iframes` site setting, and it can potentially auto-run arbitrary JS in the iframe scope, which is unintended. This issue is patched in version 3.4.4 of the `stable` branch, version 3.5.0.beta5 of the `beta` branch, and version 3.5.0.beta6-dev of the `tests-passed` branch. As a workaround, the Codepen prefix can be removed from a site's `allowed_iframes`.

CVSS 4.0
8.1 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.41% probability · 34th percentile
CISA KEV
Not listed
Weakness
CWE-1038
Affected
discourse/discourse
Source
security-advisories@github.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.